diff --git a/README.md b/README.md
index b929ab2..3300235 100755
--- a/README.md
+++ b/README.md
@@ -185,8 +185,9 @@ This extension provides 4 actions:
 
         /**
          * @param array $attributes attributes sent by Identity Provider.
+         * @param string $nameId nameId sent by Identity Provider after v2.1.1.
          */
-        public function callback($attributes) {
+        public function callback($attributes, $nameId = null) {
             // do something
         }
     }